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EP: Fachverband Extraterrestrische Physik

EP 10: Poster

EP 10.18: Poster

Mittwoch, 28. März 2007, 18:00–20:00, H46

The change of ion distribution functions at the passage over the solar wind termination shock — •Hans Jörg Fahr and Mark Siewert — Argelander Institut für Astronomie, Univ.Bonn, Auf dem Hügel 71, 53121 Bonn

Usually the Rankine-Hugoniot relations for an MHD-shock formulate conservation laws in terms of the lowest moments of ion distribution functions, mostly taken as shifted isotropic Maxwellians. Allowing for anisotropic Maxwellians this then already leads to shock relations which are not closed anymore and only permit a parametrisation by the downstream temperature anisotropy. To close the system one needs a kinetic description by means of a Boltzmann-Vlasow equation. Here we develope an appropriate form of the governing Boltzmann equation taking into account the change of the magnetic field and the plasma bulk velocity in the transition region between upstream and downstream flow regions. As we can show one can then find all the higher moments of the downstream ion distribution function and thereby close the system of Rankine-Hugoniot shock relations.